市政污泥厌氧发酵渗沥液污染物释放与热效应

为了研究污泥厌氧发酵过程中渗沥液水质污染指标随温度和时间的变化规律,以及污泥的热效应变化,分别测定30,45,60℃下厌氧发酵不同时间后污泥渗沥液的p H值、DO、TN和TOC含量,分析厌氧发酵对渗沥液污染指标的影响,通过热重-差热试验绘制45℃下不同时间的TG-DTA曲线,研究厌氧发酵对污泥热效应的影响。结果表明:新鲜污泥渗沥液p H值为7.50,随着厌氧发酵的进行,30℃下p H值上升25.7%,DO、TN与TOC含量分别下降90.0%、90.4%、74.9%,且初期外界温度越高反应速率越快;由TG-DTA曲线可知:水分散失和有机物燃烧分解致使质量损失,并分别伴随吸热和放热现象。

THE POLLUTANT RELEASE OF LEACHATE AND THERMAL EFFECT OF MUNICIPAL SLUDGE UNDER ANAEROBIC DIGESTION

In order to study the rule of pollution parameter of water quality by municipal sludge leachate changed over times and temperatures，and the thermal effect of sludge under anaerobic digestion，the paper determinated the change of pH value， contents of dissolved oxygen ( DO) ，total nitrogen ( TN) and total organic carbon ( TOC) of sludge leachate under anaerobic digestion at 30 ℃，45 ℃ and 60 ℃ separately，and also analyzed the effect of leachate pollution parameter． The curve of TGDTA was drawn by thermogravimetry and differential thermal tests under the temperature of 45 ℃， and the thermal effect was discussed． pH of sludge leachate was 7. 50 at begining，as the anaerobic fermentation in 30 ℃，the pH increased by 25. 7% and DO，TN，TOC decreased by 90. 0%，90. 4%， 74. 9% separately． The higer ambient temperature was，the faster reaction rate was． By the curve of TG-DTA，the loss of weight was caused by water desorption and organic burning，along with absorption and release of heat．